题目链接:https://vjudge.net/problem/POJ-3020 Antenna Placement Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 9995   Accepted: 4939 Description The Global Aerial Research Centre has been allotted the task of building the fifth generation of…

题目大意:原题链接 一个矩形中,有N个城市’*’,现在这n个城市都要覆盖无线,若放置一个基站,那么它至多可以覆盖相邻的两个城市.问至少放置多少个基站才能使得所有的城市都覆盖无线? 提示:看清楚题目,'*'是城市,'o'是空地,椭圆的天线覆盖范围要覆盖的是城市'*',而不是覆盖空地 解题思路:关键是建模构图 每两个相邻的星号连一条边,很明显这是一道求二分图的最小边覆盖问题(注意不是最小点覆盖) 那么接下来需要确认的是,究竟是求 有向二分图的最小边覆盖,还是求 无向二分图的最小路覆盖 因为有向和无向…

/** 题目:poj3020 Antenna Placement 链接:http://poj.org/problem?id=3020 题意: 给一个由'*'或者'o'组成的n*m大小的图,你可以用一个小圈圈圈住两个相邻的'*',问要圈住所有的'*'最少需要多少个小圈圈.(小圈圈可以相交) 思路: 先尽量圈出能圈两个且不重复圈的'*'.剩下的没有圈的'*'一定需要用一个. 所以构造二分图,求最大匹配,结果:ans = 总的'*'数量-最大匹配数*2 + 最大匹配数 = 总的'*'数量-最大匹配数:…

Antenna Placement DescriptionThe Global Aerial Research Centre has been allotted the task of building the fifth generation of mobile phone nets in Sweden. The most striking reason why they got the job, is their discovery of a new, highly noise resist…

The Global Aerial Research Centre has been allotted the task of building the fifth generation of mobile phone nets in Sweden. The most striking reason why they got the job, is their discovery of a new, highly noise resistant, antenna. It is called 4D…

Antenna Placement Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 9586   Accepted: 4736 Description The Global Aerial Research Centre has been allotted the task of building the fifth generation of mobile phone nets in Sweden. The most st…

Antenna Placement Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 6445   Accepted: 3182 Description The Global Aerial Research Centre has been allotted the task of building the fifth generation of mobile phone nets in Sweden. The most st…

题目链接: https://vjudge.net/problem/POJ-3020 题目大意: 一个n*m的方阵 一个雷达可覆盖两个*,一个*可与四周的一个*被覆盖,一个*可被多个雷达覆盖问至少需要多少雷达能把所有的*覆盖 解题思路: 把每个*城市编号,然后每相邻两个城市之间连线.这里求最少多少个雷达可以覆盖完*,就是二分图匹配中的最小路径覆盖数,但是这里的图的边是双向的.举个例子 o*o **o ooo 这里可以编号成 010 230 000 那么有边<1,3><3,1><…

传送门:hdu4185 Oil Skimming 题意:n*n的方格里有字符*和#,只能在字符#上放1*2的板子且不能相交,求最多能放多少个. 分析:直接给#字符编号,然后相邻的可以匹配,建边后无向图跑匈牙利算法,最后得到的最大匹配数/2. #include <cstdio> #include <cstring> #include <string> #include <cmath> #include <iostream> #include <…

传送门:http://poj.org/problem?id=3020 Antenna Placement Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 11098   Accepted: 5464 Description The Global Aerial Research Centre has been allotted the task of building the fifth generation of mobi…